Engineers are reportedly racing against the clock to release iOS 7 by September.

Famed Apple product designer Jony Ive has his hands deep into iOS 7 following the departure of former iOS software head Scott Forstall, leading to potential delays as he revamps the look and feel of the software. That's according to a new report at Bloomberg, which cites sources claiming that Ive is working to rid iOS of the skeuomorphism that came from Forstall's influence in order to impose a "flatter design that’s more unified and less cluttered."

As a result of this makeover, however, Apple's iOS teams are reportedly running a bit behind schedule. Engineers are "racing" to get iOS 7 to at least a demo stage before the upcoming Worldwide Developers Conference and, according to Bloomberg's sources, "internal deadlines for submitting features for testing are being set later than past releases."

That said, Apple is still expected to release iOS 7 on (its own, unannounced) schedule, which is said to be around September—around the same time the next-generation iPhone is expected to land. But it seems that the majority of the changes will be in the form of design and UI updates, with less of a focus on major feature changes. "Bigger shifts, to such features as e-mail, may not even be ready this year and may be introduced in future releases," wrote Bloomberg.

The report corroborates previous rumors that Apple has been pulling engineers off OS X 10.9 in order to move faster on iOS 7—something that Apple has done previously in order to ensure iOS receives the requisite work on time. What that means for the timing of 10.9 remains unclear; Apple has released major OS X updates in July in recent years, but the rush on iOS 7 may end up pushing 10.9—said to focus on the "power user"—until later in the year.

Update: AllThingsD also has sources speaking on the same topic, who claim iOS 7 is destined for a "de-Forstallization."

Jacqui Cheng
Jacqui is an Editor at Large at Ars Technica, where she has spent the last eight years writing about Apple culture, gadgets, social networking, privacy, and more. Emailjacqui@arstechnica.com//Twitter@eJacqui